问题
I need to listen for certain keypresses in a python terminal program without pausing execution with raw_input. I\'ve seen people use a few windows specific ways of listening for keystrokes and I\'ve seen people use large modules like tkinter and pygame which I want to avoid.
Is there a lightweight module out there that does this cross platform (at least ubuntu, windows, mac)? or is there a way to use just the event system from tkinter, pygame, etc...?
If not, how should I approach tackling this? My first thought is to redirect stdin to another process and keep checking to see if it contains one of my event keys.
edit
Thank you @unutbu for taking the time to mark this question that is 3 years old and successfully answered as a duplicate of another question whose answers do not apply to this question because I specifically asked about a non-blocking solution.
回答1:
I don't know of any cross-platform lightweight module that listens for keypresses. But here's a suggestion in case you want to implement something simple:
Check out this question on getting a single keypress at a time in the Python FAQ. You could experiment a bit with blocking reads from sys.stdin and threading. But this may only work on Unix. On Windows, you can use msvcrt.kbhit.
Combining the keypress recipe from the Python FAQ and the msvcrt module, the resulting kbhit function would go like this:
try:
from msvcrt import kbhit
except ImportError:
import termios, fcntl, sys, os
def kbhit():
fd = sys.stdin.fileno()
oldterm = termios.tcgetattr(fd)
newattr = termios.tcgetattr(fd)
newattr[3] = newattr[3] & ~termios.ICANON & ~termios.ECHO
termios.tcsetattr(fd, termios.TCSANOW, newattr)
oldflags = fcntl.fcntl(fd, fcntl.F_GETFL)
fcntl.fcntl(fd, fcntl.F_SETFL, oldflags | os.O_NONBLOCK)
try:
while True:
try:
c = sys.stdin.read(1)
return True
except IOError:
return False
finally:
termios.tcsetattr(fd, termios.TCSAFLUSH, oldterm)
fcntl.fcntl(fd, fcntl.F_SETFL, oldflags)
回答2:
Short answer: no Keypresses are system-dependent. They are interrupt-driven. They one of the basic things built into most modern OSes. They have different philosophies that can't be unified in a generic way without losing functionality.
you might try- termios = unix, posix-style file-descriptor driven
curses = portal terminal-style handling (which is a specific console-based paradigm not generic)
Python wraps certain classes of input that might come from the keyboard: e.g., sys.stdin for console inupt.
But trying to get universal keyboard input is a very general problem that's inherently platform-dependent.
回答3:
Here's how you can do it on Windows:
"""
Display series of numbers in infinite loop
Listen to key "s" to stop
Only works on Windows because listening to keys
is platform dependent
"""
# msvcrt is a windows specific native module
import msvcrt
import time
# asks whether a key has been acquired
def kbfunc():
#this is boolean for whether the keyboard has bene hit
x = msvcrt.kbhit()
if x:
#getch acquires the character encoded in binary ASCII
ret = msvcrt.getch()
else:
ret = False
return ret
#begin the counter
number = 1
#infinite loop
while True:
#acquire the keyboard hit if exists
x = kbfunc()
#if we got a keyboard hit
if x != False and x.decode() == 's':
#we got the key!
#because x is a binary, we need to decode to string
#use the decode() which is part of the binary object
#by default, decodes via utf8
#concatenation auto adds a space in between
print ("STOPPING, KEY:", x.decode())
#break loop
break
else:
#prints the number
print (number)
#increment, there's no ++ in python
number += 1
#wait half a second
time.sleep(0.5)
来源：https://stackoverflow.com/questions/5044073/python-cross-platform-listening-for-keypresses